Chris@16: // Boost.Geometry (aka GGL, Generic Geometry Library)
Chris@16: 
Chris@16: // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
Chris@16: // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
Chris@16: // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
Chris@16: 
Chris@101: // This file was modified by Oracle on 2014, 2015.
Chris@101: // Modifications copyright (c) 2014-2015 Oracle and/or its affiliates.
Chris@101: 
Chris@101: // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
Chris@101: 
Chris@16: // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
Chris@16: // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
Chris@16: 
Chris@16: // Use, modification and distribution is subject to the Boost Software License,
Chris@16: // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_GEOMETRY_ALGORITHMS_CONVEX_HULL_HPP
Chris@16: #define BOOST_GEOMETRY_ALGORITHMS_CONVEX_HULL_HPP
Chris@16: 
Chris@16: #include <boost/array.hpp>
Chris@16: 
Chris@101: #include <boost/variant/apply_visitor.hpp>
Chris@101: #include <boost/variant/static_visitor.hpp>
Chris@101: #include <boost/variant/variant_fwd.hpp>
Chris@101: 
Chris@16: #include <boost/geometry/core/cs.hpp>
Chris@16: #include <boost/geometry/core/point_order.hpp>
Chris@101: #include <boost/geometry/core/closure.hpp>
Chris@16: #include <boost/geometry/core/exterior_ring.hpp>
Chris@16: 
Chris@16: #include <boost/geometry/geometries/concepts/check.hpp>
Chris@16: 
Chris@16: #include <boost/geometry/strategies/convex_hull.hpp>
Chris@16: #include <boost/geometry/strategies/concepts/convex_hull_concept.hpp>
Chris@101: #include <boost/geometry/strategies/default_strategy.hpp>
Chris@101: 
Chris@101: #include <boost/geometry/util/condition.hpp>
Chris@16: 
Chris@16: #include <boost/geometry/views/detail/range_type.hpp>
Chris@16: 
Chris@16: #include <boost/geometry/algorithms/num_points.hpp>
Chris@16: #include <boost/geometry/algorithms/detail/as_range.hpp>
Chris@16: #include <boost/geometry/algorithms/detail/assign_box_corners.hpp>
Chris@16: 
Chris@16: 
Chris@16: namespace boost { namespace geometry
Chris@16: {
Chris@16: 
Chris@16: 
Chris@16: #ifndef DOXYGEN_NO_DETAIL
Chris@16: namespace detail { namespace convex_hull
Chris@16: {
Chris@16: 
Chris@101: template <order_selector Order, closure_selector Closure>
Chris@16: struct hull_insert
Chris@16: {
Chris@16: 
Chris@16:     // Member template function (to avoid inconvenient declaration
Chris@16:     // of output-iterator-type, from hull_to_geometry)
Chris@16:     template <typename Geometry, typename OutputIterator, typename Strategy>
Chris@16:     static inline OutputIterator apply(Geometry const& geometry,
Chris@16:             OutputIterator out, Strategy const& strategy)
Chris@16:     {
Chris@16:         typename Strategy::state_type state;
Chris@16: 
Chris@16:         strategy.apply(geometry, state);
Chris@101:         strategy.result(state, out, Order == clockwise, Closure != open);
Chris@16:         return out;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: struct hull_to_geometry
Chris@16: {
Chris@16:     template <typename Geometry, typename OutputGeometry, typename Strategy>
Chris@16:     static inline void apply(Geometry const& geometry, OutputGeometry& out,
Chris@16:             Strategy const& strategy)
Chris@16:     {
Chris@16:         hull_insert
Chris@16:             <
Chris@101:                 geometry::point_order<OutputGeometry>::value,
Chris@101:                 geometry::closure<OutputGeometry>::value
Chris@16:             >::apply(geometry,
Chris@16:                 std::back_inserter(
Chris@16:                     // Handle linestring, ring and polygon the same:
Chris@16:                     detail::as_range
Chris@16:                         <
Chris@16:                             typename range_type<OutputGeometry>::type
Chris@16:                         >(out)), strategy);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: }} // namespace detail::convex_hull
Chris@16: #endif // DOXYGEN_NO_DETAIL
Chris@16: 
Chris@16: 
Chris@16: #ifndef DOXYGEN_NO_DISPATCH
Chris@16: namespace dispatch
Chris@16: {
Chris@16: 
Chris@16: 
Chris@16: template
Chris@16: <
Chris@16:     typename Geometry,
Chris@16:     typename Tag = typename tag<Geometry>::type
Chris@16: >
Chris@16: struct convex_hull
Chris@16:     : detail::convex_hull::hull_to_geometry
Chris@16: {};
Chris@16: 
Chris@16: template <typename Box>
Chris@16: struct convex_hull<Box, box_tag>
Chris@16: {
Chris@16:     template <typename OutputGeometry, typename Strategy>
Chris@16:     static inline void apply(Box const& box, OutputGeometry& out,
Chris@16:             Strategy const& )
Chris@16:     {
Chris@16:         static bool const Close
Chris@16:             = geometry::closure<OutputGeometry>::value == closed;
Chris@16:         static bool const Reverse
Chris@16:             = geometry::point_order<OutputGeometry>::value == counterclockwise;
Chris@16: 
Chris@16:         // A hull for boxes is trivial. Any strategy is (currently) skipped.
Chris@16:         boost::array<typename point_type<Box>::type, 4> range;
Chris@16:         geometry::detail::assign_box_corners_oriented<Reverse>(box, range);
Chris@16:         geometry::append(out, range);
Chris@101:         if (BOOST_GEOMETRY_CONDITION(Close))
Chris@16:         {
Chris@16:             geometry::append(out, *boost::begin(range));
Chris@16:         }
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: 
Chris@101: template <order_selector Order, closure_selector Closure>
Chris@16: struct convex_hull_insert
Chris@101:     : detail::convex_hull::hull_insert<Order, Closure>
Chris@16: {};
Chris@16: 
Chris@16: 
Chris@16: } // namespace dispatch
Chris@16: #endif // DOXYGEN_NO_DISPATCH
Chris@16: 
Chris@16: 
Chris@101: namespace resolve_strategy {
Chris@101: 
Chris@101: struct convex_hull
Chris@101: {
Chris@101:     template <typename Geometry, typename OutputGeometry, typename Strategy>
Chris@101:     static inline void apply(Geometry const& geometry,
Chris@101:                              OutputGeometry& out,
Chris@101:                              Strategy const& strategy)
Chris@101:     {
Chris@101:         BOOST_CONCEPT_ASSERT( (geometry::concept::ConvexHullStrategy<Strategy>) );
Chris@101:         dispatch::convex_hull<Geometry>::apply(geometry, out, strategy);
Chris@101:     }
Chris@101: 
Chris@101:     template <typename Geometry, typename OutputGeometry>
Chris@101:     static inline void apply(Geometry const& geometry,
Chris@101:                              OutputGeometry& out,
Chris@101:                              default_strategy)
Chris@101:     {
Chris@101:         typedef typename strategy_convex_hull<
Chris@101:             Geometry,
Chris@101:             typename point_type<Geometry>::type
Chris@101:         >::type strategy_type;
Chris@101: 
Chris@101:         apply(geometry, out, strategy_type());
Chris@101:     }
Chris@101: };
Chris@101: 
Chris@101: struct convex_hull_insert
Chris@101: {
Chris@101:     template <typename Geometry, typename OutputIterator, typename Strategy>
Chris@101:     static inline OutputIterator apply(Geometry const& geometry,
Chris@101:                                        OutputIterator& out,
Chris@101:                                        Strategy const& strategy)
Chris@101:     {
Chris@101:         BOOST_CONCEPT_ASSERT( (geometry::concept::ConvexHullStrategy<Strategy>) );
Chris@101: 
Chris@101:         return dispatch::convex_hull_insert<
Chris@101:                    geometry::point_order<Geometry>::value,
Chris@101:                    geometry::closure<Geometry>::value
Chris@101:                >::apply(geometry, out, strategy);
Chris@101:     }
Chris@101: 
Chris@101:     template <typename Geometry, typename OutputIterator>
Chris@101:     static inline OutputIterator apply(Geometry const& geometry,
Chris@101:                                        OutputIterator& out,
Chris@101:                                        default_strategy)
Chris@101:     {
Chris@101:         typedef typename strategy_convex_hull<
Chris@101:             Geometry,
Chris@101:             typename point_type<Geometry>::type
Chris@101:         >::type strategy_type;
Chris@101: 
Chris@101:         return apply(geometry, out, strategy_type());
Chris@101:     }
Chris@101: };
Chris@101: 
Chris@101: } // namespace resolve_strategy
Chris@101: 
Chris@101: 
Chris@101: namespace resolve_variant {
Chris@101: 
Chris@101: template <typename Geometry>
Chris@101: struct convex_hull
Chris@101: {
Chris@101:     template <typename OutputGeometry, typename Strategy>
Chris@101:     static inline void apply(Geometry const& geometry, OutputGeometry& out, Strategy const& strategy)
Chris@101:     {
Chris@101:         concept::check_concepts_and_equal_dimensions<
Chris@101:             const Geometry,
Chris@101:             OutputGeometry
Chris@101:         >();
Chris@101: 
Chris@101:         resolve_strategy::convex_hull::apply(geometry, out, strategy);
Chris@101:     }
Chris@101: };
Chris@101: 
Chris@101: template <BOOST_VARIANT_ENUM_PARAMS(typename T)>
Chris@101: struct convex_hull<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> >
Chris@101: {
Chris@101:     template <typename OutputGeometry, typename Strategy>
Chris@101:     struct visitor: boost::static_visitor<void>
Chris@101:     {
Chris@101:         OutputGeometry& m_out;
Chris@101:         Strategy const& m_strategy;
Chris@101: 
Chris@101:         visitor(OutputGeometry& out, Strategy const& strategy)
Chris@101:         : m_out(out), m_strategy(strategy)
Chris@101:         {}
Chris@101: 
Chris@101:         template <typename Geometry>
Chris@101:         void operator()(Geometry const& geometry) const
Chris@101:         {
Chris@101:             convex_hull<Geometry>::apply(geometry, m_out, m_strategy);
Chris@101:         }
Chris@101:     };
Chris@101: 
Chris@101:     template <typename OutputGeometry, typename Strategy>
Chris@101:     static inline void
Chris@101:     apply(boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> const& geometry,
Chris@101:           OutputGeometry& out,
Chris@101:           Strategy const& strategy)
Chris@101:     {
Chris@101:         boost::apply_visitor(visitor<OutputGeometry, Strategy>(out, strategy), geometry);
Chris@101:     }
Chris@101: };
Chris@101: 
Chris@101: template <typename Geometry>
Chris@101: struct convex_hull_insert
Chris@101: {
Chris@101:     template <typename OutputIterator, typename Strategy>
Chris@101:     static inline OutputIterator apply(Geometry const& geometry, OutputIterator& out, Strategy const& strategy)
Chris@101:     {
Chris@101:         // Concept: output point type = point type of input geometry
Chris@101:         concept::check<Geometry const>();
Chris@101:         concept::check<typename point_type<Geometry>::type>();
Chris@101: 
Chris@101:         return resolve_strategy::convex_hull_insert::apply(geometry, out, strategy);
Chris@101:     }
Chris@101: };
Chris@101: 
Chris@101: template <BOOST_VARIANT_ENUM_PARAMS(typename T)>
Chris@101: struct convex_hull_insert<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> >
Chris@101: {
Chris@101:     template <typename OutputIterator, typename Strategy>
Chris@101:     struct visitor: boost::static_visitor<OutputIterator>
Chris@101:     {
Chris@101:         OutputIterator& m_out;
Chris@101:         Strategy const& m_strategy;
Chris@101: 
Chris@101:         visitor(OutputIterator& out, Strategy const& strategy)
Chris@101:         : m_out(out), m_strategy(strategy)
Chris@101:         {}
Chris@101: 
Chris@101:         template <typename Geometry>
Chris@101:         OutputIterator operator()(Geometry const& geometry) const
Chris@101:         {
Chris@101:             return convex_hull_insert<Geometry>::apply(geometry, m_out, m_strategy);
Chris@101:         }
Chris@101:     };
Chris@101: 
Chris@101:     template <typename OutputIterator, typename Strategy>
Chris@101:     static inline OutputIterator
Chris@101:     apply(boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> const& geometry,
Chris@101:           OutputIterator& out,
Chris@101:           Strategy const& strategy)
Chris@101:     {
Chris@101:         return boost::apply_visitor(visitor<OutputIterator, Strategy>(out, strategy), geometry);
Chris@101:     }
Chris@101: };
Chris@101: 
Chris@101: } // namespace resolve_variant
Chris@101: 
Chris@101: 
Chris@16: template<typename Geometry, typename OutputGeometry, typename Strategy>
Chris@16: inline void convex_hull(Geometry const& geometry,
Chris@16:             OutputGeometry& out, Strategy const& strategy)
Chris@16: {
Chris@16:     if (geometry::num_points(geometry) == 0)
Chris@16:     {
Chris@16:         // Leave output empty
Chris@16:         return;
Chris@16:     }
Chris@16: 
Chris@101:     resolve_variant::convex_hull<Geometry>::apply(geometry, out, strategy);
Chris@16: }
Chris@16: 
Chris@16: 
Chris@16: /*!
Chris@16: \brief \brief_calc{convex hull}
Chris@16: \ingroup convex_hull
Chris@16: \details \details_calc{convex_hull,convex hull}.
Chris@16: \tparam Geometry the input geometry type
Chris@16: \tparam OutputGeometry the output geometry type
Chris@16: \param geometry \param_geometry,  input geometry
Chris@16: \param hull \param_geometry \param_set{convex hull}
Chris@16: 
Chris@16: \qbk{[include reference/algorithms/convex_hull.qbk]}
Chris@16:  */
Chris@16: template<typename Geometry, typename OutputGeometry>
Chris@16: inline void convex_hull(Geometry const& geometry,
Chris@16:             OutputGeometry& hull)
Chris@16: {
Chris@101:     convex_hull(geometry, hull, default_strategy());
Chris@16: }
Chris@16: 
Chris@16: #ifndef DOXYGEN_NO_DETAIL
Chris@16: namespace detail { namespace convex_hull
Chris@16: {
Chris@16: 
Chris@16: 
Chris@16: template<typename Geometry, typename OutputIterator, typename Strategy>
Chris@16: inline OutputIterator convex_hull_insert(Geometry const& geometry,
Chris@16:             OutputIterator out, Strategy const& strategy)
Chris@16: {
Chris@101:     return resolve_variant::convex_hull_insert<Geometry>
Chris@101:                           ::apply(geometry, out, strategy);
Chris@16: }
Chris@16: 
Chris@16: 
Chris@16: /*!
Chris@16: \brief Calculate the convex hull of a geometry, output-iterator version
Chris@16: \ingroup convex_hull
Chris@16: \tparam Geometry the input geometry type
Chris@16: \tparam OutputIterator: an output-iterator
Chris@16: \param geometry the geometry to calculate convex hull from
Chris@16: \param out an output iterator outputing points of the convex hull
Chris@16: \note This overloaded version outputs to an output iterator.
Chris@16: In this case, nothing is known about its point-type or
Chris@16:     about its clockwise order. Therefore, the input point-type
Chris@16:     and order are copied
Chris@16: 
Chris@16:  */
Chris@16: template<typename Geometry, typename OutputIterator>
Chris@16: inline OutputIterator convex_hull_insert(Geometry const& geometry,
Chris@16:             OutputIterator out)
Chris@16: {
Chris@101:     return convex_hull_insert(geometry, out, default_strategy());
Chris@16: }
Chris@16: 
Chris@16: 
Chris@16: }} // namespace detail::convex_hull
Chris@16: #endif // DOXYGEN_NO_DETAIL
Chris@16: 
Chris@16: 
Chris@16: }} // namespace boost::geometry
Chris@16: 
Chris@16: 
Chris@16: #endif // BOOST_GEOMETRY_ALGORITHMS_CONVEX_HULL_HPP